Protractor.



H. H. LIGHTLE. PROTRAOTOR. APPLIGATION FILED JUNI: 9, 1913.

Patented May 12, 1914.

HARVEY H. LIGH'ILE, 0F SYRACUSE, NEWT YORK.

PROTRAC'I'OR.

Specification of Letters Patent.

Patented May 12, 1914.

Application led June 9, 1913. Serial No. 772,500.

To all echo/n it may concern lie it known that l, HARVEY H. Lief-rims, acitizen of the Dominion of Canada and a subject otl the. King of(,irreat Britain, residing at Syracuse, in the county oi Onondaga andState of New York, have invented certain new and useful lmprovenients inProtractors, ot which the following is a speciiication.

My invention relates to improvements in drattmens and mechanicsprotractors, and has for its object to provide a movable graduatedprotractor or segment, having two straight rulers or drawing sidesarranged at right angles to each other, and which permit the drawing ofangular lines in any direction without hindrance 'from any of thesupporting parts.

A. t'urther object is to provide meansI for determining or calculatingthe degree of any angle. as well as the dividing of a circle into thedesired number o1 parts. And ay further object is to provide novel andsimple means tor extending the straight or drawing sides ot theinstrument.

These objects are attained by the means described in theI annexedspecification, and illustrated in the accompanying drawing, m whichFigure 1 is a plan View; showing by full and dotted lines theconstruction, arrange ment and operation ot my complete device. Fig. isan edge view of the same. Figs. 3 and l are resl'iectively a. plan andan edge view ot the extension blade or ruler. Fig. 5 is an enlargedsectional view taken substantially on line 5 5 of Fig. 1; showing theconstruction of the pivot which support-s the movable preti-actor. Fig.6 is an enlarged sectional view taken on line 6t3 of Fig. l; showing theconstruction and arrangement ol'l the adjusting and (i-.lamping means.Fig. i' is a plan view ot' the movable protractor.

ln the drawing, 2 represents the protractor which preferably comprisesone part, having the center cut away, and having. similar ruling sidesor edges 3 and 4L, which are arranged to intersect at right angles toeach other. The rulers 3 and il are connected at their correspondingends, by means ot an integral arched l'n'otraetor 5, which preferablycomprises a quadrant, graduated `from 0O to 90o, and the graduations arenumbered so as to read from zero from the opposite ends of the part 5.The movable triangnlar part B-tis pivoted, and is thereforeoscillatable, by means of a screw or stud and a nut. l to one end oil anarm or bracket 7, and is thus allowed free movement or swing in oppositedirections, for drawing lilies along the edges and 4, at any anglewithin a radius of 1800. The bracket or support 7 is preferably formedA-shaped, as shown, so as to give it adequate strength. and its oppositeend is rigidly secured to a base 8 in any suitable manner, as by rivetst). The base S is pre'feably disposed at right angles to thelongitudinal center ot' the bracket 7, and its edge 8 is intended torest against, or slide freely in opposite directions along a T-sqnare,or other suitable instrun'ient (not shown). The quadrant 5 is providedwith a concentric slot ll), in which is disposed a screw ll, whichengaged by a thumb-nut 12. The slot l() is of suitable length forallowing the protractor to be swung in opposite directions on the pivot(3, as indicated by the dotted lines in Fig. 1, and it may be readilysecured in any desired position by the tightening up oi the thumb-nutl2. The base S is provided with a single graduation or mark 13, havingan arrow point or head which points to the gra duations oit the quadrant5. lVhen the movable protractor is set in the position shown in tulllines in Fig. l, the mark 13 points to lo degrees on the quadrant, andthe dra'ltsuian may draw a line along either ot the edges 2% and lat anangle of exactly 45 to the base rhen the protractor is swung or moved tothe right as far as allowed by the slot 110, and screw 11, a horizontalline may be drawn along the edge 4, while a vertical line may be drawnalong the edge It. And when the protractor is swung to the le't't thetull distance, a horizontal line may be drawn along the side 3 and avertical line may be drawn along the side 'l; (see dotted lines in Fie'.l).

lt is sometimes necessary to draw lines o1 greater length than the edges3 and l, and in order to meetsuch a contingency, l. provide an extensionbar or part 'l-l. which is pre'lrably made in the Atorni shown in Figs.l, 2, Il and l. rlhe extension is provided with a longitudinal slot l5in its oltset portion 1l to receive al' thumb-screw 1G, the threadedportion ol? which passes tln'ough the slot 15 and screws into aperforation 1G near the intersection ol. the rulers 3 and 4. Thethnmbscrew 1( .is employed tor holding thel bar T14 in place, and alsoserves as a pivot for allowing the extension to be swung in oppositedirections :tor extending the lines. 17 represents a second thumb-screwwhich passes through a perforation 17 formed near the end of the portion14 of the extension, and this screw engages corresponding threadedperfor-ations 18 in legs or parts 3 and 4.

In Fig. 1 l have shown the blade 14 in full lines set for extendino' aline drawn alone" the side 8. To shift and set the blade 111 forextending a. line drawn along the side t, the thumb-screw 17 is iii-stunscrewed and removed, and then the thumb-screw 16 is loosenedstiliiciently t0 allow the blade 14 to be drawn outwardly away from theprotractor to the extent allowed bv the slot 15. The blade 111 ma thenbe swung around until it alines with t ie ruler 4, after which it shouldbe moved in the opposite direction the full length of the slot, whichwill allow the screw 17 to be applied to the other perforation 18. Bythis means 1 am able to provide for extending the angular lines ineither direction in a quick and ready manner and accomplish theextension work with a common blade or ruler. For ordinary work theextension 11 may be dispensed with entirely. The portion 111 of theextension is preferably beveled on -its opposite sides so as to preventunnecessary thickening of the drawing edge at the point where the partsoverlap.

By constructing and arranging my oscillatable drawing` instrument asherein shown and described, a draftsman may draw lines in any directionalong either of the rulers 3 or L1, as well as at right angles toanother line, with perfect freedom and without liability of his pen orpencil coming in contact with either the bracket 7 or the base 8. Andfurthermore it is a particular object of the present invention toprovide a combined protractor and drawing` instrument which may be usedand moved freely along a T- square or other part while the ink is stillwet without danger of marring or blurring the work. By the use of'myimprovement, a di'aiitsman may draw ink lines in rapid succession, andslide the instrument from one position to another and not be required topick up the instrument and replace or readjust it after each line isdrawn.

lt is obvious that some changes or modifications niay be made in theparte and in the arrangement or' the saine, within the scope defined bythe appended claim without departing from the spirit or' my invention.

Having thus described my invention,Y what claim as new and desire tovsecure by Letters Patent, is-

in a device of the class described, the combination with a supportingframe, of a protractor pivotally connected tothe supporting frame, oneof said parts having a graduated arcuate portion and the other of saidparts having an index adapted to register therewith, said protractorincluding two ruling edges extending at an angle t0 each other, and anextension member adjustably connected to the protractor and'adapted tobe adjusted to form a continuation of either of the rulingedges of theprotractor.

ln testimony whereof I affix my signature in. presence of two witnesses.

HARVEY H. LIGHTLE.

Titnesses WM. C. ANDERSON, HARRY Dn WALLACE.

*ZE-pies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

